# Launch client jar invalid **URL:** \ **Category:** Ignition 8.3 Early Access\ **Created:** [July 30, 2025, 1:50pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145 "2025-07-30T13:50:56Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Agastheesh.Murali](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@Agastheesh.Murali](https://forum.inductiveautomation.com/u/Agastheesh.Murali)\ **Post date:** [July 30, 2025, 1:50pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/1 "2025-07-30T13:50:56Z")
Testing Ignition 8.3.0 Beta. I had to upgrade my Designer Launcher to 1.3.0 Beta-1 to access the 8.3 designer. However, I'm now unable to open any of my other 8.1.23 designers; I receive a "Launch client jar invalid" message. I ended up downgrading my designer, but this means I can no longer access 8.3. Has anyone else encountered this issue? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [July 30, 2025, 2:05pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/2 "2025-07-30T14:05:23Z")
You'd probably be seeing the same issue if you upgraded to 8.1.34 or later, when the launchclient.jar code signing verification was introduced. i.e. I don't think this an 8.3 specific issue, but rather something about your environment causing this verification to fail. You probably need to set aside some time to upgrade to the latest 8.1.x release and then, if you are seeing this issue as I suspect you will, work with support to figure out why. One cause for this I've seen is corporate firewall/MITM software modifying the JAR as its downloaded. Another can be some kind of error contacting OCSP endpoints. Hard to say without launching the designer from a command line and looking at the logs. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [July 30, 2025, 2:31pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/3 "2025-07-30T14:31:10Z")
Ok, never mind what I said above. That's not what is happening here. I can also reproduce this trying to use the 8.3 launcher against a pre-codesigning version of Ignition. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [July 30, 2025, 2:38pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/4 "2025-07-30T14:38:46Z")
Edit `~/.ignition/clientlauncher-data/designer-launcher.json`, find the `"signature.verification.strength"` key, then set the value to "LENIENT". ```python ... "signature.verification.strength": "LENIENT", ... ``` Then you should get a prompt to trust the unsigned launcher JAR file when you launch against an older Gateway. ---
**Author:** ![avaughn](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/avaughn/32/38972_2.png) [@avaughn](https://forum.inductiveautomation.com/u/avaughn)\ **Post date:** [July 30, 2025, 2:49pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/5 "2025-07-30T14:49:14Z")
Looks like this did get a section in the User Manual. The 8.3 manual does specifically mention 8.1.33 and older not working with the default of `MODERATE`. In the 8.1 launchers the default was set to `LENIENT` [8.1 Docs](https://docs.inductiveautomation.com/docs/8.1/launchers-and-workstation#signature-verification) [8.3 Docs](https://docs.inductiveautomation.com/docs/8.3/launchers-and-workstation#signature-verification) ---
**Author:** ![lcies](https://avatars.discourse-cdn.com/v4/letter/l/b3f665/32.png) [@lcies](https://forum.inductiveautomation.com/u/lcies)\ **Post date:** [August 5, 2025, 1:26pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/6 "2025-08-05T13:26:54Z")
Same issue. Try to change the parameter of .son file to `LENIENT` but when i restart the Designer Launcher it automatically roll back the parameter to `MODERATE`. - How can i fix it? Thanks ---
**Author:** ![avaughn](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/avaughn/32/38972_2.png) [@avaughn](https://forum.inductiveautomation.com/u/avaughn)\ **Post date:** [August 5, 2025, 1:38pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/7 "2025-08-05T13:38:35Z")
Try closing the Designer Launcher first and then change the value to LENIENT ---
**Author:** ![avaughn](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/avaughn/32/38972_2.png) [@avaughn](https://forum.inductiveautomation.com/u/avaughn)\ **Post date:** [August 5, 2025, 1:56pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/8 "2025-08-05T13:56:36Z")
I will say that in order to take advantage of the signature verification, all 8.1 gateways should be upgraded to 8.1.34+ ([Also for best compatibility with future upgrades to 8.3](https://docs.inductiveautomation.com/docs/8.3/getting-started/installing-and-upgrading/ignition-8-upgrade-guide/81to83-upgrade-guide#important-considerations)). Then by default Designers and Clients can be launched from 8.3 launchers. As always, before upgrading make sure to take a gateway backup. It's also advisable to test any upgrades in a development environment first. > **[Installing and Upgrading Ignition | Ignition User Manual](https://docs.inductiveautomation.com/docs/8.1/getting-started/installing-and-upgrading#upgrade-ignition)** > > The installation process for Ignition is designed to be as simple as possible. You can find installers on our Downloads page//inductiveautomation.com/downloads/ignition/. ---
**Author:** ![lcies](https://avatars.discourse-cdn.com/v4/letter/l/b3f665/32.png) [@lcies](https://forum.inductiveautomation.com/u/lcies)\ **Post date:** [August 5, 2025, 2:01pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/9 "2025-08-05T14:01:45Z")
> [@avaughn](#): > > LENIENT You're right, it works. Thanks ---
**Author:** ![Agastheesh.Murali](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@Agastheesh.Murali](https://forum.inductiveautomation.com/u/Agastheesh.Murali)\ **Post date:** [August 5, 2025, 3:31pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/10 "2025-08-05T15:31:58Z")
Thank you for the response. Yes, we are planning to upgrade to 8.1.48 in the next few months. Just have to do it across all our 15 gateways to keep them consistent. ---
**Author:** ![Agastheesh.Murali](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@Agastheesh.Murali](https://forum.inductiveautomation.com/u/Agastheesh.Murali)\ **Post date:** [August 5, 2025, 3:56pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/11 "2025-08-05T15:56:46Z")
Awesome. That worked! Thank you very much for your help! ---
**Author:** ![ntheuer](https://avatars.discourse-cdn.com/v4/letter/n/ccd318/32.png) [@ntheuer](https://forum.inductiveautomation.com/u/ntheuer)\ **Post date:** [June 5, 2026, 8:25pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/12 "2026-06-05T20:25:17Z")
Changing this to LENIENT did not work for either of my new employees. I cleared the cache. Is there anything else to try? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [June 5, 2026, 8:31pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/13 "2026-06-05T20:31:09Z")
Did you make sure the Designer Launcher was fully closed first? ---
**Author:** ![ntheuer](https://avatars.discourse-cdn.com/v4/letter/n/ccd318/32.png) [@ntheuer](https://forum.inductiveautomation.com/u/ntheuer)\ **Post date:** [June 8, 2026, 2:24pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/14 "2026-06-08T14:24:54Z")
Yes. After it failed, we reopened the .json file and confirmed that the change to LENIENT was properly saved and was not restored to MODERATE, and it was there. ---
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [July 27, 2026, 1:53pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/15 "2026-07-27T13:53:24Z")
Hi @avaughn , unfortunately not all Ignition installations can be upgrade for one reason or another - e.g. the customer does not allow for even half an hour production stop. So if you have more customers, say one with Ignition 8.1.9 and another with 8.3.x, you have to use 8.1.x launcher when you connect to customer 1 and 8.3.x launcher when you connect to customer 2. Unfortunately both launchers share the same `designer-launcher.json`and both write to it after shutdown. Consequently after connecting to 8.3,x, you cannot connect to 8.1.x, unless you edit the `json` file and change the `signature.verification.strength`parameter value ... that's really annoying. Thanks, regards ---
**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\ **Post date:** [July 27, 2026, 1:58pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/16 "2026-07-27T13:58:43Z")
> **[Deploying Pre-Configured Launchers | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.3/launchers-and-workstation/deploying-pre-configured-launchers)** > > In some cases, it may be desirable to deploy a pre-configured Launcher to remote clients. Doing so bypasses the installation process on the remote machine. The procedure to do so is outlined below, but in short it simply involves installing a... You can have multiple “portable” launchers (with different configs) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [July 27, 2026, 4:07pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/17 "2026-07-27T16:07:16Z")
> [@pgmo](#): > > have to use 8.1.x launcher when you connect to customer 1 and 8.3.x launcher when you connect to customer 2 This is not true. Latest launchers are backwards compatible. I launch everything with the launchers and the Workstation from v8.3.8. ---
**Author:** ![Agastheesh.Murali](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@Agastheesh.Murali](https://forum.inductiveautomation.com/u/Agastheesh.Murali)\ **Post date:** [July 27, 2026, 5:14pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/18 "2026-07-27T17:14:00Z")
You just need to close out all your designer sessions, in order to update this config. You do not need to take the entire server down. In other words, you do not need a downtime for this change. ---
**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\ **Post date:** [July 27, 2026, 5:17pm UTC](https://forum.inductiveautomation.com/t/launch-client-jar-invalid/109145/19 "2026-07-27T17:17:16Z")
I think @pgmo just wants to avoid repeatedly tweaking the JSON